Totalisator system



y 1963 J. H. CONDY ETAL 3,089,058

TOTALISATOR SYSTEM Filed Sept. 9, 1957 5 Sheets-Sheet 1 ENE INE I LINEGIO 6H GIZ 6I3 Gl4 TOTE OUTPUT POTENTIAL lNl/EN T025 JOHN HERBERT CONDYNOR BERT KlTZ A T TORNE Y y 1963 J. H. CONDY ETAL 3,089,058

TOTALISATOR SYSTEM Filed Sept. 9, 1957 5 Sheets-Sheet 2 RUNN TOTE OUTPUT20 67 68 69 GIO 6|! Fag .2.

INVENTORS JOHN HERBERT CONDY NORBERT KITZ ATTOIZN Y5 y 7, 1963 J. H.CONDY ETAL 3,089,058

TOTALISATOR SYSTEM Filed Sept. 9, 1957 5 Sheets-Sheet 3 INPUT //V VE/VTORS JOHN HERBERT CONDY NORBERT KITZ y 963 J. H. CONDY ETA]. 3,089,058

TOTALISATOR SYSTEM Filed Sept. 9, 1957 5 Sheets-Sheet 4 MAINSTRANSFORMER HADDON K M 5I3 INVENTORS JOHN HERBERT CONDY NORBERT KITZATTORN Y United States Patent 3,089,058 TOTALISATOR SYSTEM John H. Condyand Norbert Kitz, London, England, assignors to Bell Punch CompanyLimited, London, England, a British company Filed Sept. 9, 1957, Ser.No. 682,839 Claims priority, application Great Britain Sept. 11, 1956 13Claims. (Cl. 31584.6)

This invention is for improvements in or relating to totalisators.

It is well known that electronic devices can perform their functions ata greater speed than mechanical devices are capable of doing and theprincipal object of the present invention is to provide a constructionof totalisator which is considerably more rapid in operation and lesssusceptible to error than those conventional totalisators employed atthe present time.

A further object of the present invention is to provide a constructionof totalisator the speed of operation of which, in connection with theacceptance and registration of bets, renders unnecessary the provisionof temporary bet storage facilities in the aggregating equipment.

Other important objects and advantages sought to be achieved by thepresent invention will become apparent from the ensuing particulardescription.

The present invention will hereinafter be more particularly describedwith reference to the accompanying drawings, in which:

FIGURE 1 illustrates diagrammatically a totalisa-tor system constructedin accordance with the present invention;

FIGURE 2 illustrates diagrammatically the circuit illustrated in FIGURE1 modified in accordance with an alternative embodiment of the presentinvention;

*FIGURE 3 represents a ten cathode stepping tube marketed under the nameDekatron; and

FIGURES 4 and 4a comprise, respectively, a circuit diagram of theaggregators employed in the said totalisator, and a chart setting outthe values of the various components employed.

It is considered desirable to describe, at the outset, certain symbolsemployed in FIGURE 1 in order that the said figure may be readilyunderstood when the detailed description starts. Thus,

represents a gating device or gate which is capable of transmitting anoutput pulse only when it receives two simultaneous input pulses;

represents an element which, upon receiving an impulse,

represents an element which, upon receiving an impulse,

ice

transmits a very narrow pulse at the end, only, of the said impulse; and

I Output Clear LS2 represents a trigger or bi-stable device which, onceit has been set, applies voltage until it is cleared. It is set by apulse on the line marked Set and is cleared by a pulse on the linemarked Clear.

In addition to the symbols set out above, rectangular blocks areemployed to denote electronic multi-stage counters or aggregators,ticket-issuing machines and commutator segments. A detailed descriptionof the construction and mode of operation of the ticket issuing machinesthus diagrammatically illustrated is believed to be unnecessary since aticket issuing machine of the kind intended to be employed is fullydescribed and illustrated in United States Patents Nos. 1,886,626;1,886,769 and 2,020,594.

The following description relates to a totalisator which has beenlimited as regards the number of component parts in the interests ofsimplicity and in the belief that a person skilled in the art will bereadily capable of applying the general principles of the inventionexplained herein to a considerably larger installation if required.

Therefore, referring to FIGURE 1 it will be noted that there areillustrated therein two ticket-issuing machines T.I.M.1 and T.I.M.2 eachcapable of dealing with three runners, 1, 2, and 3, and three categoriesof stake, namely, win, place and show. The machine T.I.M.1 is associatedwith a set of commutator segments 1 to 6 and the machine T.I.M.2 isassociated with a set of commutator segments 7 to 12. The commutatorsegments 1, 2 and 7, 8 are so arranged as to be swept by a pair ofshorting brushes BPZ and the commutator segments 3, 4, 5, 6 and 9, 10,11, 12 are so arranged as to be swept by a pair of shorting brushes BP3.Further, the machine T.I.M.1 is associated with a pair of commutatorsegments 13 and 14 and the machine T.I.M.2 is associated with a pair ofcommutator segments 15 and 16, the said commutator segments 13, 14 and15, 16 being so arranged as to be swept by a pair of shorting brushesBPl.

It will be convenient to point out at this juncture that the segments 1to 6 and 13, 14 associated with the machine T.I.M.1 and the segments 7to 12 and 15, 16, associated with the machine T.I.M.2 will, in practice,be disposed in a plurality of concentric circles, the pairs of shortingbrushes BPl, BPZ and BP3 all being carried by one rotating arm and beingso aligned as to sweep on the same radial line. The commutator segmentswill preferably consist of metallic segments set in insulating material,the insulating material being formed as a circular disc in which allthose segments which, in the drawing, are disposed in the samehorizontal line are disposed in the same circular track. The disc,herein after referred to as the commutator disc, and the metallicsegments may be made in accordance with printed circuit techniques.

Reverting to FIGURE 1, it will be noticed that the segments 1, 2 and 7,S swept by the brush BP2 are wider than the segments 3, 4, 5, 6 and 9,10, 11, 12 swept by the brush BP3 and for this reason the pulsesgenerated by the segments 1, 2 and 7, 8 being swept by the brush BP2will be called wide pulses whilst the pulses generated by the segments3, 4, '5, 6 and 9, 10, 11, 12 being swept by the brush BP3 will becalled narrow pulses.

The commutator segments 13 and 15 have voltage permanently connected tothem and thus the pairs of segments 13, 14 and 15, :16 generate Wideimpulses, known as clock impulses, for synchronising purposes when theyare swept sequentially by the brush BPl. The impulse generated, forexample, by the sweeping of the segments, 13 14 is applied to one inputof a gate G1, the impulse generated by the sweeping of the segments 15,16 being applied to a gate G2.

The output of a bi-stable device T1 is applied to the segment 1 and, byway of the pair of shorting brushes BP2, to the segment and a set ofthree stake switches, S1, S2 and S3. The segment 1 is connected to thesegment 3 so that the output of the bi-stable device T1 is also appliedto a set of three runner switches C1, C2 and C3 when the pair ofshorting brushes BP3 sweeps the segments 3, 4.

The segments 7, 8, 9, 10 and the bi-stable device T2 are similarlyconnected.

A set of three runner lines and a set of three stake lines are common tothe machines T.I.M.1 and T.I.M.2, the stake switches S1, S2, S3, and therunner switches 01, C2, C3 in each machine being connected to theappropriate lines as indicated in FIGURE 1.

The runner lines are connected by means of buffer diodes to an elementE1, the switchesCl, C2 and C3 .being, therefore, connected when closedto the element E1 by the buffer diodes 17, 18 and 19, respectively. Theoutput of the element E1 is applied to the bi-stable device T3 at theinput marked Clear. The output of T3 is applied to or removed from:

(a) One input of each of three gates G3, G4 and G5, and (b) Thecommutator segments 5 and 11.

according to the state thereof during the preceding interval of time.

The stake lines are connected to the gates G3, G4 and G5, the stakeswitches S1, S2 and S3 being connected, respectively to G5, G4 and G3.The output of gate G3 is connected to one input of each of three gatesG6, G7 and G8, the outputs of the gates G4 and G5 being connected to oneof the inputs of the gates G9, G10, G11 and G12, G13, G14, respectively.The second input of each of the gates G6, G9, G12 is connected to theline associated with runner 3 (namely the line connected to the runnerswitch C3), the second input of each gate G7, G10, G13 is connected tothe line associated with runner 2 and the second output of each gate G8,G11, G14 is connected to the line associated with runner 1.

The output of each gate G6 to G14 is connected to an aggregator,

(a) Gates G6, G7, G8 being connected to aggregators labelled,respectively, runner 3, runner 2, runner 1. Each runner aggregator isconnected, by means of a buffer diode, to an aggregator labelled WinTotal;

(b) Each gate G9, G10, G11 being connected, as in (a) above, to anaggregator, each aggregator being connected, via a buffer diode, to anaggregator labelled Place Total; and

(c) The arrangement being similar to that in (a) and (b), the finalaggregator being labelled Show Total.

The Show Total, Place Total and Win Total aggregators are each connectedto a Tote Output line 20 by means of'a buffer diode. The line 20 isconnected to the input of an element E2, the output of which is appliedto the device T3 at the input marked Set.

The issue of a ticket will now be described in connection with T.I.M.1:

It should be noted at the outset that the bi-stable devices T1 and T2are normally off or do not apply voltage at the outputs thereof whilstthe device T3 is normally on or applies voltage to the two lines 21 and22.

In order to issue a ticket on a particular runner, the operator firstconditions the machine for the kind of stake required (namely, win,place or show), thereby causing, for example, the switch S2 to close.Assuming that the person placing the stake has chosen runner 3, theoperator depresses a runner key associated with that particular runner,thereby closing the switch C3. The switch K is automatically closedshortly after closure of the switch C3, thereby calling the machineT.I.M.1 into action by applying a voltage to gate G1.

When the brushes BP1 short the segments 13, 14, voltage is applied to anelement 23 which sends an extremely narrow pulse to gate G1, this pulsebeing timed to occur at the beginning of the first clock pulse to begenerated by the sweeping of the segments 13, 14 after the switch K inT.I.M.1 has closed. The gate G1, having voltage applied thereto throughthe switch K and having received a pulse from the element 23, sends apulse which triggers T1, thereby causing T1 to apply voltage to thesegment 1. Since segment 3 is connected to segment 1, voltage is alsoapplied to segment 3.

It is necessary to point out here that the segments 1 and 2 are greaterin width than the combined widths of segments 3 and 5, for example.Further, the segments 1 and 2 are so disposed relatively to the twopairs of segments 3, 4 and 5, 6 that the brushes BP2 contact segments 1,2 before contacting segments 3, 4 and also fall off segments 5, 6 beforefalling oif segments "1, 2. Further, segments 3, 4 are separate fromsegments 5, 6. Similar remarks apply to the segments 7, 8, 9, 10, 11 and12 associated with T.I.M.2.

When brushes BP2 short segments 1, 2 voltage is applied via the saidbrushes, segment 2, and switch S2 to the line which represents the typeof stake involved; in this case, a place stake. The place line, as itwill hereafter be called, is connected to one input of gate G4. Sincethe output of the device T3 is applying a voltage to one of the inputsof each of the gates G3, G4, G5, the gate G4 will now have voltageapplied at both inputs and will, as a result, transmit a pulse to theline which commons the gates G9, G10 and G11.

Shortly after the brushes BP2 contact segments 1, 2, the brushes BP3contact and short-circuit segments 3, 4, as a result of which an impulseis sent via the said brushes BP3, the segment 4 and the switch C3 to theline which represents the runner involved, namely, runner 3. Runner 3line is connected (11) via buffer diode 19 to the element E1, and (b) toone input of each of the gates G6, G9, G12, and therefore the impulsegenerated by the brushes BP3 sweeping segments 3, 4 is simultaneouslyapplied to theelement E1 and the said gates G6, G9 and G12. Bydefinition, the element E1 transmits a very narrow pulse at the end ofthe impulse generated by the brushes BP3 sweeping the segments 3, 4 and,therefore, just before the brushes BP3 falloff the segments 3, 4 theelement E1 emits a pulse which clears T3, thereby cutting off the supplyof voltage to the lines 21 and 22.

Reverting to the gate G4, it will be remembered that this gatetransmitted a pulse to the line which commons one of the inputs of eachof the gates G9, G10, G11. Moreover, the runner 3 line is connected toone of the inputs of each of the gates G6, G9, G12 and thus the impulsegenerated by the brushes BP3 shorting the segments 3, 4 is applied tothe said inputs of gates G6, G9, G12. It will, therefore, be appreciatedthat gate G9 receives two overlapping impulses at its two inputs, thiscausing G9 to transmit an impulse to the runner 3 aggregator.

When runner 3 aggregator has recorded the fact that a bet has beenplaced in respect of runner 3, the said aggrcgator transmits a pulse tothe place total aggregator. When the place total aggregator has recordedthe fact that a place bet has been staked the said aggregator transmitsan impulse to the tote output line 20 and, via the line 20, to theelement E2 which, at the end of the impulse transmitted by the placetotal aggregator, transmits a narrow impulse to the device T3. Thedevice T3 is set by this narrow return impulse and thereby voltage isapplied once again to the lines 21 and 22.

It will be convenient to note, at this juncture, that when the device T3is cleared, thereby removing voltage from the lines 21 and 22, voltageis not applied any longer to one input of each of the gates G3, G4 andG5. Until the device T3 is set by a narrow impulse being transmitted bythe element E2, the totalisator is not able to accept and register anyfurther bets.

When the device T3 is set and re-applies voltage to the lines 21 and 22,voltage is applied to the segments 5 and 11 associated, respectively,with T.I.Ml and T.I.M.2. After the brushes BP3 fall off segments 3, 4and after a further short interval of time, the said brushesshort-circuited the segments 5, 6, the segment 6 of which is connectedto a self-holding relay and to the clear input of the device T1. Thus,when the brushes BP3 short-circuit the segments 5, 6, an impulse is sentboth to the self-holding relay and to the device T1.

Operation of the said relay (a) breaks the line connecting the Kcontacts of T.I.Mul to the gate G1 and (b) initiates the ticket issuingcycle. The impulse which operates the said relay also clears T1, therebyremoving potential from the segments 1 and 3, and, since the brushes BP3fall off the segments 5, 6 before the brushes BP-2 fall off the segments1, 2, the potential is removed from the segments 1, 2 whilst the brushesBP2 are short-circuiting them.

When the ticket has been issued, T.I.M.1 releases those keys of themachine which have been depressed, the self holding relay falls off andthereby T.I.M.1 is re-connected to G1 in readiness for the next cycle.

The above detailed description of the operation of the totalisator inconnection with T.I.M.1 applies also to T.I.M.2 and, therefore, thesequence of operations as applied to T.I.M.2 will be deemed to beunderstood.

Additional safeguards against the undesired issue, by any ticket issuingmachine in the system, of a ticket may be added and one such preferredsafeguard is illustrated in FIGURE 2 in which only those parts of FIGURE1 which are directly associated with T.I.M.-1 and which are modifiedhave been illustrated. It will be remembered that the brushes BPSshort-circuit the segments 5, 6, of which the segment 5 has potentialapplied thereto by T3. When the brushes BP3 short-circuit the segments5, 6, an impulse is sent to clear the device T1, thereby removingpotential from the segments 1 and 3. Towards the end of the pulsegenerated by the device T1 being turned off, an element E10 (FIGURE 2)sends a narrow pulse to a device T10, the output of which is connected((1) to a self-holding relay and (b) to a delay 31 The arrangement issuch that when T10 is turned on or set an impulse is sent to theself-holding relay which breaks the line connecting the K contacts tothe gate G1 and which initiates the ticket issuing cycle. The said relaythen falls off, as hereinbefore described, and by this time the delay 30sends a pulse to clear or turn off the device T15.

It will be appreciated that T.I.M.2 is provided with an element E11, adevice T11, a delay 31 and a self-holding relay, the operation of all ofwhich is as described above, and it will further be appreciated thateach ticket issuing machine in or associated with a totalisator systemis provided with such a safeguard circuit as that described above.

Each of the aggregators illustrated in FIGURES 1 and 2 consists of aplurality of ten cathode stepping tube counters, marketed under the nameDekatron and hereinafter referred to as such, interconnected by a noveltype of carry-over circuit. A mathematical check on the performance ofeach aggregator unit as a whole is provided, both the carry-over circuitand the checking circuit having been introduced to minimise the risk ofmisfunction on the part of any aggregator unit passing unnoticed.

Before the circuit illustrated in FIGURE 4 is described in detail, themanner of operation of a Dekatron will be considered very carefully.

A Dekatron is a gas-filled cold-cathode stepping tube which usually hasten electrodes known as cathodes. A glow can be maintained between acommon anode and any one, and only one, of the above-mentioned cathodesand the glow can be transferred from one cathode to another by suitablepulsing. By referring to a particular cathode as the 0 cathode, to theone next to it as the 1 cathode and so on, decimal counting is possibleor indeed counting in any notation is possible dependent upon the numberof cathodes with which the tube is provided.

Before the carry-over system which it is proposed to employ betweensuccessive Dekatrons can be discussed it becomes necessary to considerthe manner in which the glow is transferred from one cathode to the nextadjacent cathode:

In the Dekatron assembly there are two electrodes between each pair ofadjacent cathodes, these electrodes being known as guides 1 and guides2, respectively. All guides 1' are commoned and similarly all guides 2'are commoned. Normally the voltage difference between each of thecathodes and the common anode is kept greater than the voltagedifference between each of the guides and the anode, so that the glowmust reside on a particular cathode.

When it is desired to step the glow from one cathode to the nextadjacent cathode the voltage difference between guides 1 and the anodeis made greater than that between the anode and cathode on which theglow resides (that is, guide 1 is driven negative compared with the saidcathode) so that the glow jumps from the said cathode to the nearestguide 1'. After a predetermined interval of time the guides 2' aredriven negative compared with the cathode and the glow is shared by theadjacent guides 1 and 2/ because the negative voltage reading of allguides 1' and 2' is the same. After a further predetermined interval oftime, all guides 1 are restored to the normal at rest voltage and guide2' will take over the whole glow. 'When finally the guides 2' arerestored to the normal at rest voltage the glow jumps to the nearestcathode (which is nearer to guide 2 than the cathode from which isstarted) because, in order to go back to the cathode from which itstarted, the glow would have to jump over guide 1.

It now becomes important to discuss how the pulses on the guides 1' and2 are derived. These are normally derive-d by means of a single pulsewhich is applied through a voltage divider 35, 36 to guide 1 and, via anintegrating circuit 33, 34, to guide 2. It will be seen from FIGURE 3that the integrating circuit to guide 2' merely consists of a resistor33 and capacitor 34 and that the delay required between switching offthe pulses to guide 1' and guide 2' is simply provided by the chargestored in the capacitor 34.

A very important point arises in this connection and this is the factthat, after the drive pulse has disappeared, the glow resides on guide 2until such time as the charge on the capacitor 34 has droppedsufficiently to allow it to step to the next cathode.

It is a feature of Dekatron circuitry that the amplitude of thecarry-over pulse obtained when a Dekatron passes through the zeroposition, is insufficient, without amplification, to step the Dekatronin the next higher order and, therefore, a carry-over amplifier isalways provided.

The output of the zero cathode of a Dekatron is usually connected to theinput of the carry-over amplifier via a conventional resistance/capacitycoupling.

It is common practice to make the carry-over amplifiers independentself-contained circuits. These sometimes take the form of a simpleamplifier, cut off until a carryover pulse occurs, which the amplifiermagnifies sulficiently to drive the next stage.

Sometimes the carry-over pulse is used to trigger off a pulse shapingcircuit of conventional design which produces a pulse of predeterminedamplitude or width or indeed both, which pulse is used once more todrive the next stage.

All the above carry-over amplifier units suffer from the followingdisadvantages:

(1) Being separate units, the failure of one of them may pass undetectedfor a long time;

(2) Each unit uses its own supply of current, with consequent increasein power requirement where there is a plurality of units;

(3) The fluctuations in load on the power unit may be violent in thecase of amplifiers being turned on from a cut-off condition, so thatstabilisation of the power unit may be essential.

The carry-over circuitry illustrated in FIGURE 4 and employed in theaggregators illustrated in FIGURES l and 2 is a variation of thelong-tailed pair circuit Well known in the art.

Referring to FIGURE 4, the triode V4b always forms one of the valves ofthe pair and the grid potential of V4b is normally higher than that ofV2a, V212, V3a, V3b and V4a so that V41) is normally conductive.Accordingly, current flows through R36 and R31 and voltage is developedacross R31 which is sufiicient to prevent V2a, V2b, V3a, V3b, V4a fromconducting.

However, if, for example, V2a is pulsed by either an input or carry-overpulse, it will be made conductive so that current will flow through itsanode circuit and R31. This additional current through R31 will cause anincreased voltage drop across it, with the result that V4b will becomenon-conductive. The current through the anode circuit of V2a will causepulses to be applied to the guides of the second Dekatron Vi11 to stepit and increase its setting by unity. At the end of the input orcarry-over pulse, V2a will become non-conductive and V4b will againbecome conductive.

A single current can be used for all the carry-over circuits because ithas already been established that, after a drive pulse has been appliedto a carry-over amplifier, the glow in the driven Dekatron will notsettle on a cathode until some time after the drive pulse hasdisappeared, with the consequence that while the drive pulse is onanother stage is not capable of producing a carry-over pulse and thesame source of common current can be safely used for all the carry-overamplifiers.

It will be appreciated that the circuit described above with referenceto FIGURE 4 possesses the following advantages:

(I) Only one current is required for all the carry-over amplifiers;

(II) The drain on the power supply is a minimum;

(III) All stages of the counter are driven by a current pulse and areindependent of valve characteristics;

(IV) The load on the power supply is virtually constant as the sameamount of current is taken from it at all times;

(V) The use of suitable time constants enables all stages to operatewith identical height and width pulses;

(VI) All carry-over amplifiers are connected to the same source ofcurrent so that many faults (such, for example, as one of the carry-overamplifiers being permanently on) are readily detected in that they areof the catastrophic type rather than of the intermittent type.

A further degree of security is achieved by connecting all the heatersof the carry-over valves in series so that heater failure in one valveputs the whole circuit out of action.

The novel feature of the above circuit compared with a conventionallong-tailed pair lies in the fact that, in the conventional circuit, twotriodes share a common cathode load and according to the grid settingcurrent (the same current) will flow through one valve or the other;whereas, in the carry-over circuit described above, the current isabsorbed by whichever valve happens to be carrying and the long-tailedpair may be formed by V.4b and any other valve according to the previoushistory of the counting circuit.

Another novel feature of the circuit of the present invention is thedesign of a carry-over circuit for Dekatrons on similar counting tubeswhich is based on the realisation that a delay (in the case of theDekatron, the delay forms part of the drive circuit) introduced at asuitable point in the circuit will cause only one carry-over amplifierto be operative at a given time. One result of this is that a commonsource of current may be used, with what may be regarded as theconsequent advantages of long-tailed pair technique which make itpossible, as already explained, to make all stages of the counter oraggregator operate with standardised identical pulses, a condition mostlikely to lead to absolute reliability.

Even with the carry-over circuit described with reference to FIGURE 4and the connection of all valves in that circuit in the series heatermanner a further check on the correcter correct functioning of theaggregator is desirable.

It will be realised that one of the properties of the carry-over circuitillustrated in FIGURE 4 is the fact that every time one of the variouscarry-over amplifiers carries, current is taken away from V.4b, so thatevery time a carrytoccurs V.4b gives out a pulse from its anode circuit.These pulses from V.4b are reshaped by a conventional pulse shaper V.8which is similar to V1 and the reshaped pulses are used to drive anotherDekatron V.9.

It follows that, at the end of a count V.9 will register (modulo 10) thetotal number of carries that have occurred during that count. Suppose,for example, that 5336 impulses have been sent into the counter oraggregator there will have been the following carries:

From units to tens S 33 From tens to hundreds 53 From hundreds tothousands 5 and V.9 will therefore read: 1.

If all the figures standing in the aggregator (except the units) areadded up (modulo 10) they should give 1 as the answer:

5+3+3=11 11 (modulo 10)=l Therefore, all that it is necessary to do atthe end of a count is to add up (modulo 10) all figures except the unitsfigure standing in the aggregator and compare them with the check figurestanding in V.9. If there is a discrepancy, there has been a miscount.

The above check will pick up a m-iscount provided that the number ofimpulses missed is not a multiple of 10 and therefore an accuracy of canbe claimed for the checked result.

In the system described above,,units readings are ignored. The checkingsystem can be. extended to the units readings simply by replacing V.1 bya circuit identical with V.2a, V.2b, V.3a, V..3b and V.4a joined to thesame source of current. Under these new conditions V.4b will send out apulse for every pulse sent into the counter, namely, including the unitsstage, as well as for every carry. Assuming that the number of pulsessentintothe 9 counter is the same as in the preceding example, V.9 wouldreceive the following number of pulses:

Input pulses 5336 Carries:

From units to tens 533 From tens to hundreds 53 From hundreds tothousands and V.9 will therefore read: 7. The check figure being 7, theresult of adding together (modulo the figures standing in theaggregator, units included, should he 7:

5+3+3+6=17 17 (modulo 10) =7 Suppose that on one occasion the carry-overbetween the hundreds and the thousands had failed to step the thousandsDekatron in spite of the fact that a drive pulse had been generated. Thefinal count would be 4336, the figures of which when added together(modulo 10) would give 6. However V.9 would still in these circumstancesread 7 and therefore the fact that an error or miscount had occurred insome stage would be detected.

The carry-over circuit described above suffers from certain drawbackswhich are not of any significance in totalisator work but which shouldbe mentioned. Owing to the common current source, the circuitillustrated in FIGURE 4 would not work at the maximum speed of whichDekatrons are capable if ten stages of counting were used instead ofsix, because, as the carry propagates from stage to stage at the samespeed as the Dekatron in stage 1 steps, it follows that all propagationmust be completed before stage 1 has stepped through another completecycle and has generated yet another carry if the best use is to be madeof the Dekatrons. Naturally, though, if stage 1 is stepped at a slowerspeed than the rate of carryover propagation, more than ten stages ofDekatrons can be used.

The complete checking circuit, units included, proposed above can, forthe same reasons, only be used at the expense of Dekatron counting speedbecause, in using the complete checking circuit, it becomes necessary tolimit the rate at which pulses are fed into stage 1 to 1 to 6 to allowthe carry-over sufficient time to propagate.

The maximum speed of counting of the type of Dekatron employed in FIGURE4 is 4000 counts per second. If this is the speed used in carry-overpropagation, the rate of input to stage 1 must be limited to:

?:666 pulses per second Of course, such a counting speed is still wellover five times as fast as the totalisator requirement so that, despitethe above so-called drawbacks, the completely checked circuit wouldalmost certainly be used in totalisator work.

It should be emphasized that there is associated with each Dekatron avisual display from which the contents of a Dekatron may be read. Thedisplay consists, in one embodiment, of a numeral wheel whichautomatically adjusts the setting of itself so as to indicate visuallythe setting of the Dekatron. Such a construction has been described inUnited States patent applications Serial Nos. 682,376, 682,394 and682,396, all filed September 6, 1957, and basically comprises a numeralwheel, a series of contacts each connected to a cathode of theassociated Dekatron and a relay-operated arresting device. Whilst theDekatron is being pulsed the numeral wheel hunts, thus rotatingconstantly, but when the Dekatron is not being pulsed any longer thenumeral wheel, upon which there is disposed a pair of wiper contacts,bridges the live contact connected to the cathode on which the glow isresiding. The relay hereinbefore referred to operates and the numeralwheel is arrested, displaying the amount recorded by the Dekatron.

Valves V.5a, V.5b, V.6a, V.6b, V.7a and V.7b are em ployed as amplifiersto operate the arresting relays of the visual display by means of whichthe hunting numeral wheel is caused to display visually the amountstanding in the associated Dekatron.

The power unit illustrated in FIGURE 4 is conventional and of asimplicity rendered possible by the type of circuits used.

It will be appreciated and it is to be understood that a trigger circuitconsisting of a pair of valves may either consist of that pair of valveswithin one and the same glass envelope or consist of each valve of thepair being enclosed within a separate glass envelope.

We claim:

1. An electronic aggregator including a plurality of multi-cathodegas-filled electron discharge glow tubes coupled by carry-overamplifiers to form a counting chain, wherein each carry-over amplifiercomprises a trigger circuit which has two conduction phases and whichdraws substantially the same current in each of its two conductionphases.

2. An electronic aggregator as claimed in claim 1, wherein each triggercircuit comprises a pair of valves.

3. An electronic aggregator as claimed in claim 2, wherein the twovalves are cathode-coupled.

4. An electronic aggregator as claimed in claim 3, wherein eachcarry-over amplifier comprises a long-tailed pair.

5. An electronic aggregator as claimed in claim 2, wherein one valve ofeach pair is common to a plurality of carry-over amplifiers.

6. An electronic aggregator as claimed in claim 5, wherein one valve ofeach pair of valves is common to all carry over amplifiers.

7. An electronic aggregator comprising a plurality of multi-cathodegas-filled electron discharge glow tubes, a. plurality of firstelectronic valves operatively connected each between two of saidmulti-cathode tubes to form a counting chain, a second electronic valve,each of said valves having an anode, a cathode, and a control electrode,a common cathode load for said second valve and at least some of saidfirst valves, and means for applying a constant potential to the controlelectrode of said second valve.

8. An electronic aggregator as claimed in claim 7, wherein said firstvalves and said second valve are hard valves.

9. An electronic aggregator comprising a series of multi-cathodegas-filled electron discharge glow tubes, a plurality of firstelectronic valves each operatively connected between the tubes of aseparate pair of said multicathode tubes to form said multi-cathodetubes into a counting chain, a second electronic valve, each of saidvalves having an anode, a cathode, and a control electrode, a cathodeload common to all said valves, and means for applying a constantpotential to the control electrode of said second valve, whereby onlyone of said valves can be conductive at a time.

10. An electronic aggregator comprising a plurality of multi-cathodegas-filled electron discharge glow tubes each including an anode, aplurality of cathodes, and a plurality of guide electrodes betweenadjacent of said cathodes, said aggregator further comprising aplurality of first electronic valves each including an anode, a cathode,and a control grid, each of said valves being disposed in circuitbetween the tubes of a separate pair of said tubes with a cathode of onetube of such pair coupled to the control grid of that valve and with theanode of that valve coupled to the guide electrodes of the other tube ofsuch pair, a second electronic valve including an anode, a cathode and acontrol grid, a cathode load common to all of said valves, and biasmeans to cause said second valve to conduct except when one of saidfirst valves is conducting.

11. An electronic aggregator comprising a plurality of multi-cathodegas-filled electron discharge glow tubes, carry-over amplifiersoperatively connected between adjacent ones of said multi cathode tubesto form said multicathode tubes into a counting chain, an electronicvalve, a common power supply for all said amplifiers and said valve, andmeans for ensuring that said valve is conductive except when one of saidcarry-over amplifiers is operating to pass a carry from one of saidmulti-cathode tubes to the next tube in the chain.

12. An electronic aggregator as claimed in claim 11, including means forcounting the number of times said valve is rendered non-conductive.

13. An electronic aggregator comprising a plurality of rnulti-cathodegas-filled electron discharge glow tubes,

carry-over amplifiers operatively connected between said multi-cathodetubes to form a counting chain, an elec tronic valve,- means forensuring that said valve is conductive except when one of saidcarry-over amplifiers is Referenees Cited in the file of this patentUNITED STATES PATENTS 2,167,513 Johnston July 25, 1939 2,636,681 ReevesApr. 28, 1953 2,680,561 Handley June 8, 1954 2,788,940 Terry et a1. Apr.16, 1957 2,810,099 Townsend Oct. 15, 1957 2,811,310 Caldwell Oct. 29,1957 2,837,281 Wright et a1. June 3, 1958 2,886,240 Linsman May 12, 19592,927,246 Read Mar. 1, 1960

1. AN ELECTRONIC AGGREGATOR INCLUDING A PLURALITY OF MULTI-CATHODEGAS-FILLED ELECTRON DISCHARGE GLOW TUBES COUPLED BY CARRY-OVERAMPLIFIERS TO FORM A COUNTING CHAIN, WHEREIN EACH CARRY-OVER AMPLIFIERCOMPRISES A TRIGGER CIRCUIT WHICH HAS TWO CONDUCTION PHASES AND WHICHDRAWS SUBSTANTIALLY THE SAME CURRENT IN EACH OF ITS TWO CONDUCTIONPHASES.